Deleting a member of your organization will not affect the data in any way. Deleting a member from your organization should be done soon after an employee or team member leaves a team. The member will not have access to your organization (data, information, etc.) in Motivity once removed.
To delete a member, start on the organization's home screen, select, "Members" then select the member you wish to remove. From there, click on the three vertical dots in the top right corner and then select "Remove".